Technologies such as microelectronics, micromechanics and biotechnology have created a high demand for structuring and probing specimens within the nanometer scale. Micrometer and nanometer scale process control, inspection or structuring, is often done with charged particle beams, e.g., probing or structuring is often performed with charged particle beams which are generated and focused in charged particle beam devices. Examples of charged particle beam devices are ion beam implanters, electron microscopes, electron beam pattern generators, ion microscopes as well as ion beam pattern generators. Charged particle beams offer superior spatial resolution compared to photon beams, due to their short wave lengths at comparable particle energy.
Ion beam devices can be used for a plurality of applications. Examples include the preparation of cross sections of semiconductor devices by ion milling, the production of microstructures by ion milling, the writing of structures like quantum dots, quantum wires, magnetic nano-dots etc. by ion implantation, sputtering, inspection or other applications. Thereby, different milling rates, sputtering rates or other characteristics, which may require different beam currents can be desirable. The beam current may, for example, be adjusted by the amount of collimation of a condenser lens.
However, applying different beam paths and, at the same time, providing mass separation by Wien filters, sectors, and the like is difficult to obtain. In light thereof, e.g., Teicher and Tiunov (“Design of an achromatic mass separator for a focused ion beam,” SPIE Vol. 2014 Charged Particle Optics (1993)/85) propose the use of two ExB filters, whereby the pivot point of such a system can be moved along the optical axis. However, such a system is complicated to align, expensive, and difficult to calibrate for different beam paths.